Gyratory crusher with external dynamic balancing assembly

ABSTRACT

A gyratory crusher, with externally mountable dynamic balancing means, is disclosed having a lower frame, a stationary upright upper frame mounted on the lower frame, and a generally conical crushing head arranged within a concave mounted within the upper frame to define a crushing chamber between the concave and the head. The head is supported by the lower frame and driven to gyrate around a central axis through the upper frame. A pair of upright balance shafts are provided and arranged with one on each of opposite sides of the crusher and the balance shafts are driven to rotate in synchronism with the gyratory movement of the head around the axis of the concave. A pair of balance weights are provided with one balance weight attached to each balance shaft to rotate therewith. The balance weights each have a center of gravity offset from the balance shaft to counterbalance forces generated by the gyratory movement of the head about the upper frame axis.

United States Patent 1 1 3,809,324 COOk May 7, 1974 GYRATORY CRUSHER WITH EXTERNAL Primary Examiner-Granville Y. Custer, Jr.

DYNAMIC BALANCING ASSEMBLY Inventor: Eugene B. Cook, Appleton, Wis.

Allis-Chalmers Corporation, Milwaukee, Wis.

Filed: Nov. 10, 1972 Appl. No.: 305,424

Assignee:

References Cited I UNITED STATES PATENTS 7/1969 Allen 241/214 X 1/1964 Johnson 241/207 8/1939 Rider 241/210 X 3/1931 Symons 241/210 X FOREIGN PATENTS OR APPLICATIONS H1938 Great Britain 241/210 Attorney, Agent, or FirmArthur M. Streich [57] ABSTRACT A gyratory crusher, with externally mountable dynamic balancing means, is disclosed having a lower frame, a stationary upright upper frame mounted on the lower frame. and a generally conical crushing head arranged within a concave mounted within the upper frame to define a crushing chamber between the concave and the head. The head is supported by the lower frame and driven to gyrate around a central axis through the upper frame. A pair of upright balance shafts are provided and arranged with one on each of opposite sides of the crusher and the balance shafts are driven to rotate in synchronism with the gyratory movement of the head around the axis of the concave. A pair of balance weights are provided with one balance weight attached to each balance shaft to rotate therewith. The balance weights each have a center of gravity offset from the balance shaft to counterbalance forces generated by the gyratory movement of the head about the upper frame axis.

4 Claims, 2 Drawing Figures GYRATORY CRUSHER WITH EXTERNAL DYNAMIC BALANCING ASSEMBLY BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to rock crushing machines having a generally conical head and a surrounding stationary upper frame that define therebetween an annular crushing chamber, and in particular to such a machine having an external dynamic balancing assembly.

2. Description of the Prior Art Gyratory crushers are sometimes provided with internal balance weights to counterbalance forces generated by the gyratory movement of the head about a central vertical axis through the upper frame. Examples of such crushers are shown in U.S. Pat. Nos. 1,796,413 of 1931; 3,118,623 of 1964; and 3,454,230 of 1969.

Not all gyratory crushers, and in particular not all large or primary gyratory crushers, are manufactured with internal balancing as shown in the aforesaid patents. The reason for this is that large primary crushers have been designed for operation in installations where the crusher is bolted to a massive concrete foundation and in such installations dynamic balance weight is not required. Recently however, it has become desirable to mount primary crushers on skids, relatively light slabs, or even wheeled portable platforms, and to mount an unbalanced crusher on such structures will achieve less than desired operation. It is to this problem that the present invention is directed.

SUMMARY OF THE PRESENT INVENTION Among the objects achieved by the present invention is that a new and improved gyratory crusher is provided having an external dynamic balancing assembly, and in particular, an external dynamic balancing assembly is provided that can be attached to a gyratory crusher manufactured without internal balance weight.

A preferred embodiment of the present invention involves a gyratory crusher having a lower frame, a stationary upright upper frame mounted on the lower frame, and a generally conical crushing head arranged within a concave mounted within the upper frame to define a crushing chamber between the concave and the head. The head is supported by the lower frame and driven to gyrate around a central axis through the upper frame. Dynamic balancing of the crusher is achieved by providing a pair of upright balance shafts arranged with one on each of opposite sides of the crusher and the balance shafts are driven to rotate in synchronism with the gyratory movement of the head around the axis of the upper frame. A pair of balance weights are provided with one balance weight attached to each balance shaft to rotate therewith. The balance weights each have a center of gravity offset from the balance shaft to counterbalance forces generated by the gyratory movement of the head about the upper frame axis.

Other features and objects of the invention that have been attained will appear from the more detailed description to follow with reference to an embodiment of the present invention shown in the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 of the accompanying drawing shows diagrammatically a side elevation, partly in section, a gyratory crusher according to the present invention; and

FIG. 2 is a view taken along line IIII in FIG. 1 and viewing the structure in the direction indicated by arrows.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. I, a gyratory crusher is shown comprising a lower frame 1, an upper frame 2 mounted on the lower frame 1, and a spider 3 arranged on top of the upper frame 2. The spider 3 has a rim 4 secured to the top of the upper frame 2 and radial arms 5 that support a hub bearing housing 6 centrally over rim 4 and upper frame 2. A gyratable crushing head 7 is mounted on a shaft 8 which is fulcrumed in hub bearing housing 6. Upper frame 2 includes an annular concave 9 arranged within upper frame 2, and the concave 9 and crushing head 7 cooperate to define therebetween an annular crushing chamber 10.

Means are provided for supporting the lower end of shaft 8 and driving shaft 8 and head 7 for gyratory movement around a vertical axis X-Y central of concave 9. Such means may include an eccentric sleeve 12 journaled in a portion 13 of frame I and around the lower end of shaft 8. The eccentric sleeve 12 may be rotated by a drive shaft 14 to gyrate shaft 8 and head 7 in a manner such as is disclosed in U.S. Pat. No. 2,667,309. The eccentricity of the rotary sleeve 12 carries the lower end of head 7 as shown in FIG. 2 closer to concave 9 on one side (the right-hand side as viewed in FIG. 2) than on the opposite side thereof (the lefthand side as viewed in FIG. 2) to provide a nip N to crush rock between the outer circumference of head 7 and the inner circumference of concave 9, generating forces that will be dynamically balanced by counterbalancing means which will now be described.

With reference to FIG. 1 and FIG. 2, the counterbalancing means may include a pair of housings 21, 22 each having a portion, which may include such as lugs 23, adapted to be bolted or otherwise attached by any suitable means such as bolts 23a to flanges 24 projecting from vertical side wall portion 25 of frame 1. Balance members, here shown as vertical balance shafts 27, 28 are journaled for rotation in the respective housings 21, 22. Drive means are provided to rotate the balance shafts 27, 28 in synchronism with each other and in synchronism with the gyratory movement of the head 7 around the concave axis X-Y. The drive means may include a sheave 30 mounted on the crusher drive shaft 14, and a pair of timing drive belts 31, 32. Both drive belts 31, 32 may engage sheave 30 with belt 31 also engaging a sheave 33 drivingly connected to balance shaft 27, and with belt 32 also engaging a sheave 34 drivingly connected to balance shaft 28. The driving connections between the sheaves 33, 34 and the balance shafts 27, 28 may be identical and by way of example with regard to sheave 33, may include a shaft 35 carried by one or more bearings 37 (see FIG. 2). A bevel gear 39 mounted on shaft 35 may be provided to engage a bevel gear 41 on shaft 27 and transmit rotary movement of shaft 35 to shaft 27. The effective diameters of sheave 30, sheaves 33, 34 and bevel gears such as 39, 41 are suitably chosen to rotate balance shafts 27, 28 in synchronism with the gyratory movement of crusher shaft 8 and head 7 around the axis X-Y. A balance weight 43 and 44 is attached to each balance shaft 27 and 28 respectively, with each balance weight 43 and 44 having a center of gravity C.G. see FIG. 2) offset from the shaft 27 and 28 to which it is attached. The balance weights 43, 44 are positioned see FIG. 2) 180 from the center of gravity C0. of the shaft 8 and head 7 to counterbalance the center of gravity C6. of the shaft 8 and head 7 which is offset from axis X-Y because of the eccentricity of sleeve 12.

In the operation of the crusher that has been described, rock to be crushed is fed into chamber 10. Power applied by means (not shown) to shaft 14 rotates sleeve 12 about concave axis X-Y. Because of the eccentricity of the inner circumferential surface of sleeve 12 relative to its outer circumferential surface, crusher shaft 8 and head 7 gyrate around concave axis X-Y carrying head 7 closer to concave liner 9 at N on one side thereof (the right-hand side when in the position shown in FIG. 2) where rock is nipped and crushed. The location of the nip N moves around the inner circumference of concave liner 9 as the head 7 gyrates around axis X-Y and generates forces that are dynamically counterbalanced by the balance weights 43, 44 rotating with shafts 27, 28 in synchronism with the gyration of head 7 around axis X-Y. Adjustment to achieve desired synchronism may be achieved by positioning weights 43, 44 relative to head 7, before belts 31, 32 are placed around sheaves 33, 34. Thus external dynamic balancing is provided by the described assembly which can be attached to a crushermanufactured without internal dynamic balancing weight.

From the foregoing detailed description of the present invention it has been shown how the objects of the present invention have been attained in a preferred manner. However, modification and equivalents of the disclosed concepts such as readily occur to those skilled in the art are intended to be included in the scope of this invention. Thus, the scope of the invention is intended to be limited only by the scope of the claims such as are or may hereafter be, appended hereto.

The embodiments of the invention in which an exclusive property or privilege is claimed, are defined as follows:

l. A gyratory crusher having a frame, a stationary concave supported by the frame, a generally conical crushing head within the upper frame supported concave to define a crushing chamber therebetween, means for supporting and driving the head relative to the frame and concave for gyratory movement of the head around a central axis through the concave, and

means counterbalancing forces generated by the gyratory movement of the head, the counterbalancing means comprising:

a. a rotatable balance shaft substantially parallel to the central axis of the concave and external to the concave and frame;

b. drive'means connected to the balance shaft to rotate the balance shaft in synchronism with gyratory movement of the head around the concave axis; and

c. a balance weight attached to the balance shaft to rotate therewith and having a center of gravity offset from the balance shaft to counterbalance the forces generated by the gyratory movement of the head about the concave axis.

2. A gyratory crusher according to claim 1 in which a pair of balance shafts are provided, each balance shaft supports a balance weight attached thereto, the balance shafts are arranged with one on each of opposite sides of the crusher, a drive means to each balance 'shaft rotates the balance shafts in synchronism with the gyratory movement of the head around the axis, and both balance weights are offset from their supporting shafts to counterbalance the forces generated by the gyratory movement of the head about the concave axis.

3. A gyratory crusher according to claim 2 in which each balance shaft with. its attached balance weight is enclosed in a protective housing connected to the crusher frame.

4. An external dynamic balancing assembly for. gyratory crushers comprising:

a. a pair of housings each having a portion adapted to be attached to opposite vertical side wall portions of a gyratory crusher frame;

b. a balance shaft journaled within each housing for rotation-about an axis which is vertical when the housing is attached to a gyratory crusher in operating position;

c. drive means connected to both balance shafts to rotate the balance shafts in synchronism with each other and adapted to be rotated in synchronism with gyratory movement of a gyratory crusher to which the housings are adapted to be attached; and

tive to counterbalance forces generated thereby. 

1. A gyratory crusher having a frame, a stationary concave supported by the frame, a generally conical crushing head within the upper frame supported concave to define a crushing chamber therebetween, means for supporting and driving the head relative to the frame and concave for gyratory movement of the head around a central axis through the concave, and means counterbalancing forces generated by the gyratory movement of the head, the counterbalancing means comprising: a. a rotatable balance shaft substantially parallel to the central axis of the concave and external to the concave and frame; b. drive means connected to the balance shaft to rotate the balance shaft in synchronism with gyratory movement of the head around the concave axis; and c. a balance weight attached to the balance shaft to rotate therewith and having a center of gravity offset from the balance shaft to counterbalance the forces generated by the gyratory movement of the head about the concave axis.
 2. A gyratory crusher according to claim 1 in which a pair of balance shafts are provided, each balance shaft supports a balance weight attached thereto, the balance shafts are arranged with one on each of opposite sides of the crusher, a drive means to each balance shaft rotates the balance shafts in synchronism with the gyratory movement of the head around the axis, and both balance weights are offset from their supporting shafts to counterbalance the forces generated by the gyratory movement of the head about the concave axis.
 3. A gyratory crusher according to claim 2 in which each balance shaft with its attached balance weight is enclosed in a protective housing connected to the crusher frame.
 4. An external dynamic balancing assemBly for gyratory crushers comprising: a. a pair of housings each having a portion adapted to be attached to opposite vertical side wall portions of a gyratory crusher frame; b. a balance shaft journaled within each housing for rotation about an axis which is vertical when the housing is attached to a gyratory crusher in operating position; c. drive means connected to both balance shafts to rotate the balance shafts in synchronism with each other and adapted to be rotated in synchronism with gyratory movement of a gyratory crusher to which the housings are adapted to be attached; and d. a balance weight attached to each balance shaft with each balance weight having a center of gravity offset from the shaft to which it is attached, and each balance weight and balance shaft being positionable relative to a gyratory crusher to which the housings are adapted to be connected, and operative to counterbalance forces generated thereby. 